Dreye权威释义

conj.

prep.

unless and until

直到……才
I will not believe it unless and until he tells me so.
除非他亲口对我说，否则我决不相信。

同义参见:

以上来源于：《英汉大辞典》

conj.

except when; if not.

ME: from on or in (assimilated through lack of stress to un-¹) + less.

以上来源于：《简明牛津英语词典》